1. Field of the Invention
This invention relates to a compact pumping apparatus and to a fast and reliable method for the cold sterilization and lubrication of a dental handpiece.
2. Prior Art
Certain communicable diseases such as, for example, hepatitis, AIDS (acquired immune deficiency syndrome), herpes, and the like, could be inadvertently spread at a dental office when a dental handpiece which has been used in the mouth of an infected patient is later used in the mouths of uninfected patients. Because the dental handpiece is not adequate sterilized or is not at all sterilized after each use, bacteria and other harmful microorganisms may undesirably be transmitted to the mouth of a healthy patient who is treated with the same, contaminated handpiece.
More particularly, a forward spray orifice, common to most conventional dental handpieces, is known to emit an air/water spray or mist in order to cool a work surface within the patient's mouth. When the spray is terminated, an aerosol mixture within the patient's mouth (including saliva, blood and water) is frequently sucked back through the orifice and into the interior of the handpiece. Moreover, bacteria laden aerosol may also be conveyed from an infected patient's mouth to the interior of the handpiece via worm or loose seals at the cutting head of the handpiece. Consequently, in the event that the dental handpiece is not sterilized after each use, a patient in whose mouth the handpiece is later used might become infected with disease, particularly when the handpiece cuts blood vessels during work within such a patient's mouth.
One effective way to sterilize a handpiece is by means of high temperature. In this case, the dentist places the handpiece in an autoclave for approximately 20-45 minutes at a temperature of 300 degrees F. The handpiece must then be cooled down for an additional 3 hours before it is ready for further use. However, such a process of heating and cooling a handpiece is very time consuming and, therefore, requires that the dentist have access to many handpieces with which to treat different ones of his patients. Moreover, heating the handpiece to a high temperature for long periods of time is known to age the seals and damage the bearings of the handpiece turbine assembly, thereby necessitating frequent repair and increased cost. Accordingly, some dentists are reluctant to subject their handpieces to the high temperatures needed to adequately destroy potentially harmful bacteria and microorganisms after each patient has been treated.
Another way to sterilize a handpiece is by means of cold sterilization. In this case, the handpiece is immersed in a reservoir of liquid disinfectant. However, such liquid disinfectant is typically harmful and tends to erode the seals and precision bearings of the internal turbine assembly. What is more, liquid disinfectants frequently leave behind a solid residue which sometimes causes the turbine assembly to become unbalanced, particularly at high speeds of rotation. After continuous out-of-balance rotation, the turbine assembly may fail, thereby also necessitating repair and increased costs. What is still more, the use of a reservoir of liquid disinfectant has generally limited the effectiveness of the cold sterilization process to the exterior of the handpiece. Unfortunately, such a conventional process is not well suited to sterilizing the internal exhaust and intake ports and associated tubing into which disease carrying aerosol may be carried and trapped during the treatment of a contaminated patient.
Consequently, no economic and effective way of internally and externally sterilizing a dental handpiece is known which can be accomplished in a relatively short time without risking degradation to the turbine assembly.